Transformer Connections 1 - Instant Video
This 64-minute video explains the common types of overhead transformers and how they are connected. Covers both single-phase and three-phase connections, with emphasis on three-phase connections. Some theory, mostly practical examples. How to make single-phase transformer connections, how to make three-phase connections in wye-wye and delta-delta configurations, and how to verify that a replacement transformer is the right one.
Transformer Basics – 14 minutes
Defines the term transformer. Identifies common types of overhead distribution transformers. Identifies the common designations used for primary and secondary bushings. Lists and explains basic information found on a transformer nameplate.
Primary Systems – 7 minutes
Differentiates between delta and wye primary systems. Explains the phasor diagrams used to illustrate delta and wye systems. Lists and explains basic requirements for connecting transformers to delta and wye systems.
Single-Phase Transformer Connections – 9 minutes
Demonstrates how single-phase transformers can be connected to supply single-phase service.
Three-Phase Primary Connections – 11 minutes
Describes and demonstrates a three-phase delta primary connection, using three single-phase transformers. Describes and demonstrates a three-phase wye primary connection using three single-phase transformers.
Delta Secondary Connections – 13 minutes
Shows a three-phase delta secondary connection with 0 degrees angular displacement. Differentiates between delta-delta phasor diagrams with 0 degrees and 180 degrees of angular displacement. Explains the expected secondary voltages of a delta-delta connection.
Wye Secondary Connections – 10 minutes
Explains how the coils that make up the secondary windings are connected to make wye connections. Uses phasor diagrams to illustrate a wye-wye connection. Shows how a wye-wye connection with 0 degrees of angular displacement is made. Explains how secondary voltages are supplied from a wye-wye connected three-phase bank.